Vacuum dispersion coating process



May 13, 1930, w. A. F. PFANHAUSER 1,758,531

VACUUM DISPERSION COATING PROCESS Filed Oct. 10, 1927 /n rental.-

Patented M... 13, .1930

UNITED, sTArE-s 'JPYATVENT- OFFICE WILHELM ANTON FRANZ IPI'ANHAUSER, OF LEIPZIG, GERMANY, ASSIGNOB TO amm- SOHAFT FUR ELEKTRODENZERSTAUBUNG'M. B. 3., OF BOHLITZ-EHBENBERQ W' LEIPZIG, GERMANY, A CORPORATION OF GERMANY vacuum nrsrnasron con'rme rnocrss Application filed October 10, 1927, Serial No. 225,130, and. in Germany October 22, 1828.

ter a high voltage is applied, it has been found that the material being coated is very easily scorched and burned due to the high 'heat which is present in the vacuum container or vessel.

My invention provides a process in which the material being .treated is artificially cooled so that, irrespective of the temperature attained in the vessel, delicate fa rics ma be properly coated without the liability of eing burne r otherwise harmed. ThlS latter provision is of particular advantage in connection with delicate lace and other easily combustible materials. 'According to my invention, the cooling of the sensitive articles is accomplished by passing said articles over'acooling system during the coating process. This cooling system, as

hereinafter described, comprises a plurality of pipes through which a cooling medium is circulated, the material under treatment heingconducted in close proximity or in actual contact'with thecooling system, the latter thereby forming a support for the material during its travel through the system. I find that in this manner it is possible to cool even readily combustible organic substances -;such

as textile fabrics,-lace, paper, knitted ggo ods and similar substances so effectively thatany e0 tirely eliminated. This difliculty has heretofore restricted-the practice of the dispersioncoating process to material which did not readily ignite or become scorched. I find this process particularly advanta geous also when readily fusible metals are being coated. Heretofore, in my experience,

7 it has not been possible to utilize a dispersion process in coating such metals.

' Referring now more particularly to the drawing, Figure 1 is an elevational, sectional burning or scorching of the material is en-.

view of an apparatus in which myproccss may be practiced, it being understood, of course, that the showing is diagrammatic and is not intended to represent all thedetails which may be present in such process; and

Figure shows a plan view of a portion of the coohng supports and the material passin thereover. v

11 carrying out my improved process, a

vacuum vessel 1 is utilized, a coohng system comprising P125318 2 being positioned within said vessel.

medium entering the supporting coils through an mlet pipe 3 and passing out of the vessel through exitpipe 4. Drums 5-5 g 3' suitable cooling medium may be circulate through said pipes 2, said and 6-6 are mounted within the container 1 and are provided with a belt or material-supporting member 7' which may be unrolled from the ri ht-hand drums 5 and wound up on the left and drums 6. The rotation of these drums may be effected by any suitable known means, the latter having been omitted "from the drawing for purposes bf simplifi cation. I

The material to be treated or coated is indicated at 8 it being observed that the material in this particular illustration is-continuous and is so placed on the belt or support- 7 that it is supported on and passes along with said belt.

High tension electrical energy is applied to dispersion electrodes 9- and 10 which are positioned between the two traveling supports 7, these electrodes being alternately posltively and negatively charged, as shown. Dlrecting screens 1111 are provided to insure the proper positioning and disposition of the dispersed metal from the electrodes.

One of the marked advantages of my system of coating articles comprises the provision of the traveling supports 7. These supports are made of suflicient width to insure that none of the dispersed metal will impinge upon, or be collected by,'the cooling pipes 2. It will be understood that the supporting member 7 is a good conductor of heat. Moreover, said supports 7 are supported in their movements by the coils 2, wherefrom a sufiicient support is gained for the belt and at the same time the latter is so effectively cooled that the material 8, supported on-said belt, is not subject to burning or scorching.

I have found that if the articles to be coated with metal are not large enough or wide enough to covercomplet el'y the cooling surface, the dispersed materlal will be deposited on the cooling supports 2, and this results in a'very expensive waste of material since it is impossible to recover the metal which is thus undesirably deposited 011 the cooling supports. Moreover, if no support is used, and long pieces of material such as textile fabrics, Webs of paper, and the like are being treated and are drawn through the apparatus, it frequently happens that an undesirable condition is present in the coat ing operation because the soft, easily movable substances, such for instance as fine lace and like materials, are drawn into folds so that the portions overlap and in consequence faulty coatings are produced at such points.

As above indicated, such defects are overcome by securing the articles to be treated to the belt supports 7 which are drawn along in proximity to the electrodes 9 and 10. These supports 7 move in close contact to, or directly upon, the cooling supports and the articles'8 are directly on the supports, as bestshown in Fig. 2. As heretofore mentioned, I make such supports of good heat conducting material and so dlmension the same that they overlap entirely the zone in which dispersed metal is likely to be disposed. The range of such zone is indicated in Fig. 2 by the dot and dash line. Any metal which is deposited on the supports 7 is, of course, recovered outside of the vacuum Vessel without interfering with the coating process.

While I have described but one apparatus in which my improved process may be practiced, it is obvious that many other devices may be suggested in which my improved process may be practiced with economy and I therefore desire that my invention be broadly interpreted and limited only by the scope of the appended claims and by the prior art.

I claim: 1. A process for coating articles with metals by electrodes dispersed in vacuum which consists in passing said articles in proximity to the electrodes and simultaneously directly cooling the articles.

2. The process for coating articles with metals by electrodes dispersed in vacuum which consists in passing said articles in close proximity to the dispersing electrodes and simultaneously supporting said articles on artificially cooled supports.

3. A process for coating articles with metals by electrode dispersion in vacuum while simultaneously cooling the articles, comprising passing the said articles in close proximity to the dispersing electrodes while sup-- ported upon artificially cooled supports which are supplied with a cooling medium from without the vacuum vessel in which the said coating operation is taking place.

4. A process for coating articles with metals by electrode dispersion in a vacuum,- comprising passing the said articles in close proximity to the dispersing electrodes while supported upon a traveling conveying belt which is in close contact with artificially cooled supporting means that are supplied with a cooling medium from without the vacuum vessel in which the said coating operation takes place.

5. A process as in claim?) comprising the use of a conveying belt consisting of a material that is a good conductor of heat.

6. A process for coating articles with met als by electrode dispersion in a vacuum, which comprises temporarily attaching said articles to a movable heat-conducting conveying belt, passing said belt and attached articles in close proximity to electrically dispersing electrodes while said belt is in close contact with supporting means that are sup plied with a cooling medium from Without are artificially refrigerated from sources without the vacuum apparatus, and rewinding the conveying belt and attached articles upon a second-drum likewise positioned in said vacuum'apparatus.

In witness whereof, I have hereunto subscribed my name. I

WILHELM ANTON FRANZ PIFANHAUSER. 

